I´d like to say that there is something disconcerting about a fire type that is inherently punished in sun.
To go by Gamefreak standards: every other Dry Skin Pokemon is given another option besides Dry Skin (although yes, they are not particularly viable, they still give the option to run those mons outside of one specific niche, rain).
To go by Smogon's standards: Like my teachers in high school used to say, AP stands for Answer the Prompt. So, Can we Answer the Prompt? Let me refer to the first sentence, where we are tasked with "creat[ing] a Pokemon who's typing, while normally considered poor defensively and/or offensively, becomes a strong selling point of the Pokemon itself via help from an ability, stats, and/or movepool". I will specifically consider CAP3's poison typing in this argument, though a 1.5x boost to fire moves in sun is also one of the strong selling points of a fire type. Poison typing's saving grace is the ability to absorb toxic spikes, a skill particularly useful to sun teams. So what I am saying is, I agree, let's not give this 'mon an ability which makes it inherently more useful in sun, but at the same time, lets reward those who wish to use the poison typing to its advantage.
If CAP3 is not punished simply by being alive on a sun team, then when placed on a designated sun team, it becomes a failsafe against rain teams (while handily absorbing toxic spikes), meaning that CAP3's original niche becomes expanded to other scenarios, not simply replaced. In summary, to take away the opportunities for a boosted fire stab and poison absorbency in sunlight from a Fire/Poison mon is directly against "creat[ing] a Pokemon who's typing, while normally considered poor defensively and/or offensively, becomes a strong selling point". Thanks for listening, and you stay classy, Smogdiego.
To go by Gamefreak standards: every other Dry Skin Pokemon is given another option besides Dry Skin (although yes, they are not particularly viable, they still give the option to run those mons outside of one specific niche, rain).
To go by Smogon's standards: Like my teachers in high school used to say, AP stands for Answer the Prompt. So, Can we Answer the Prompt? Let me refer to the first sentence, where we are tasked with "creat[ing] a Pokemon who's typing, while normally considered poor defensively and/or offensively, becomes a strong selling point of the Pokemon itself via help from an ability, stats, and/or movepool". I will specifically consider CAP3's poison typing in this argument, though a 1.5x boost to fire moves in sun is also one of the strong selling points of a fire type. Poison typing's saving grace is the ability to absorb toxic spikes, a skill particularly useful to sun teams. So what I am saying is, I agree, let's not give this 'mon an ability which makes it inherently more useful in sun, but at the same time, lets reward those who wish to use the poison typing to its advantage.
If CAP3 is not punished simply by being alive on a sun team, then when placed on a designated sun team, it becomes a failsafe against rain teams (while handily absorbing toxic spikes), meaning that CAP3's original niche becomes expanded to other scenarios, not simply replaced. In summary, to take away the opportunities for a boosted fire stab and poison absorbency in sunlight from a Fire/Poison mon is directly against "creat[ing] a Pokemon who's typing, while normally considered poor defensively and/or offensively, becomes a strong selling point". Thanks for listening, and you stay classy, Smogdiego.